DE2937840A1 - METHOD FOR THE HYDROXYLATION OF SHORT-CHAIN ALIPHATIC MONO- OR DIOLEFINS - Google Patents

Abstract

1. A process for the hydroxylation of 3-chloro-2-methylpropene-1, of straight- or branched- chain monoolefins which are unsubstituted or are already substituted by 1 or 2 hydroxyl groups and have 4 to 7 carbon atoms and a terminal or internal double bond, of straight- or branched- chain monoolefins which are unsubstituted or are already substituted by 1 or 2 hydroxyl groups and have from 8 to 10 carbon atoms and an internal double bond, or of straight- or branched- chain diolefins having from 4 to 10 carbon atoms, characterised in that the olefin to be hydroxylated is reacted at a temperature of from 30 to 80 degrees C with less than 2 mols of formic acid and less than 2 mols of hydrogen peroxide, in each case per mol of double bond to be hydroxylated, formic acid of a concentration of from 20 to 100% by weight is used and hydrogen peroxide of a concentration of less than 50% by weight is used, and the concentration of the hydrogen peroxide in the aqueous phase of the reaction mixture is maintained below 15% by weight for the complete duration of the reaction.

Description

293784Q

GERMAN GOLD AND SILVER SCHETDEANSTALT

VO RM AL S RO E S S LE R Veissfrauenstrasse 91 6000 Frankfurt

Process for the hydroxylation of shorter-chain aliphatic mono- or diolefins

The invention relates to a process for the hydroxylation of 3-chloro-2-methylpropen-1, of straight-chain or branched, unsubstituted or already substituted by 1 to 2 hydroxyl groups monoolefins with 4 to 7 carbon atoms and terminated or internal double bond, before straight-chain or branched, unsubstituted or already through

up to 2 hydroxyl groups substituted monoolefins with b to 10 carbon atoms and internal double bond or of straight-chain or branched diolefins with k to 10 carbon atoms.

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Hydroxylation is to be understood as meaning that there are two hydroxyl groups on each of the olefinic double bonds are accumulated. During the hydroxylation of the monoolefins, vicinal diols are formed, if one or two hydroxyl groups are already present, the corresponding triols or tetrols the hydroxylation of the diolefins produces unsaturated ones Diols or saturated tetrols.

The method according to the invention is characterized in that that the olefin to be hydroxylated at a temperature between 30 and 80 C with less than 2 moles of formic acid and less than 2 moles of hydrogen peroxide, each per mole to be hydroxylated Double bond, converts, formic acid with a concentration between 20 and 100 percent by weight and Hydrogen peroxide with a concentration of less than 50 percent by weight is used, and the Concentration of hydrogen peroxide in the aqueous Phase of the reaction mixture during the total duration the implementation keeps below 15 percent by weight.

The reaction is preferably carried out at a temperature between 45 and 60.degree. The formic acid is advantageously used in an amount from 0.2 to 0.8 mol per mol of double bond to be hydroxylated, the hydrogen peroxide advantageously in one Amount of 1.1 to 1.5 moles used per mole of double bond to be hydroxylated. A hydrogen peroxide is preferred with a concentration of 15 to 40 Weight percent used.

As starting materials for the inventive Process are 3-chloro-2-methylpropen-1, straight

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Chain monoolefins with 4 to / carbon atoms, such as butene-1, butene-2, pentene-1, hexene-1, heptene-1 or heptene-3 and branched-chain monoolefins with 4 to 7 carbon atoms, such as 2-methylpropene-1, 3 -Methylbutene-1, 3,3-dimethylbutene-1, 2, J-dimethylbutene-1, 2, 3-dimethylbutene-2, 2-methylpentene-1, 2-methylpentene-2, 3-methylpentene-2 or 2 -Athylbutene-I. The monoolefins to be used can also already be substituted by 1 to 2 hydroxyl groups. Examples of such substances are buten-1-ol-3, buten-2-ol-1 (crotyl alcohol), butene-2-diol-1,4 , 3-methylbutene-3-ol-1, 3-methylbutene-2- ol-1 or 2-meth3 ^r lbuten-3-ol-2. While with the monoolefins with a maximum of 7 carbon atoms the double bond

at any point, i.e. at the end of the chain or in the Inside the chain, monoolefins with S to 10 carbon atoms are the reaction accessible to the process according to the invention only,

_nn if the double bond is inside the chain.

Examples of such substances are 2,4,4-triraethylpentene-2, 1,2-di- (tert-butyl) -ethylene or decene-5 Also the monoolefins with Ö to 10 carbon atoms can already be substituted by 1 to 2 hydroxyl groups, as in 2-ethylhexen-2-ol-1.

Finally, straight-chain or branched diolefins can also be used in the process according to the invention with 4 to 10 carbon atoms, such as butadiene, Isoprene, hexadiene-1.5 or decadiene-1.9 »to the corresponding Tetroles are implemented.

The process according to the invention is preferably carried out at normal pressure. However, as to achieve a manageable reaction speed, the reaction

temperature should not be below 30 C, it understands

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It goes without saying that in the case of olefins with a boiling point below 30 C, overpressure must be applied is. In this case it is then expedient to choose the reaction temperature so that the pressure does not exceed 10 bar. The implementations surprisingly, the process according to the invention proceeds despite the relatively mild reaction conditions very smooth and lead within acceptable reaction times to high yields of the desired di-, tri- or tetrols.

In the practical implementation of the invention Procedure is preferably the entire to be used Formic acid presented together with the olefin and the hydrogen peroxide slowly added. However, it is also possible to initially only have a part, for example about one third of the total amount of olefin to be hydroxylated, along with the total amount of formic acid and the hydrogen

peroxide and the remaining amount of what is to be hydroxylated: n Add olefins slowly. In each case the reaction mixture is stirred vigorously. For improvement of the conversion, an appropriate reaction time is recommended, after all reaction participants in the Reaction vessels are combined.

After the reaction has ended, the reaction products are usually present in dissolved form in the aqueous phase.

of> For some purposes such aqueous solutions can be used directly. In most cases But not only will the residual hydrogen peroxide content have a disruptive effect, it is too it is desirable that the di-, tri- or tetrols formed are isolated in purer form. Then come for

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7th
the processing of various measures into consideration.

If a second phase separates out of the reaction mixture, a phase separation can first be carried out will. In many cases it is then advisable to use that which is practically only contained in the aqueous phase To a large extent decompose hydrogen peroxide. The decomposition can be caused by prolonged standing at a higher temperature (digestion) or by the action of a suitable catalyst (e.g. passing over a platinum fixed bed contact) or by combining of these two measures.

Vuη is conveniently the reaction mixture neutralized and with a suitable solvent, for example ethyl acetate, extracted. From the Extract, the solvent is distilled off and the remaining residue of crude di-, tri- or tetrol, if appropriate by heating under reduced pressure freed from any remaining water. Alternatively, the neutralization of the reaction mixture can also be used contained formic acid can be dispensed with. Then it is appropriate, either the thickening

_ Continuously in the manner of steam distillation and continue until the Distillate only contains small amounts of formic acid. Or the aromatic acid abortion becomes discontinuous made in such a way that the

OQ residue after the main amount has been driven off Water was added to formic acid again, again thickens and repeated this operation several times. The remaining one

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Residual crude di-, tri- or tetrol can then be freed of any volatile constituents still present by heating under reduced pressure.
5

The crude di-, tri- or tetrols obtained in this way are present with degrees of purity of about 8 to 96 ° . If further purification is required, this can be effected in the usual way by recrystallization or by fractional distillation under reduced pressure.

The method according to the invention is followed by the following Examples explained in more detail. Unless otherwise stated, percentages are in in all cases percentages by weight.

Example 1:

1 mol of crotyl alcohol (72 g) was mixed and mixed with 0.5 mol of formic acid (98 ig; 23 g) and with 1.5 mol of H ₂ O ₃ (15 <i ± g \ 340 g) in a stirred apparatus with a reflux condenser attached stirred at 60 ° C. for 8 hours. The system was 1-phase and contained 3.9 <£ H "0. The batch was passed over a 30 cm long NV 40 column which was filled with 100 ml of fixed bed catalyst (θ, 1% platinum on Berl saddles). After passing through, H “0 could no longer be detected analytically.

The batch was then refluxed for 2 hours and in vacuo (up to 100 C sump temperature at 12 Torr)

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thickened. A residue of 102 g remained, which was then distilled in a high vacuum (0.1 torr) became. The fraction that passes between 125 and 130 C. (= 92 g) consisted of methyl glycerine.

Example 2:

In an apparatus according to Example 1, 1 mol of 3-chloro-2-methyl-propene-1 (91 ^{g) was mixed with 0.75 mol of formic acid (90 c} «ig; 35 g) and at 60 ° C. with 1.5 mol H ₂ O ₂ (kO <= ig; 128 g) in the course of 6 hours

offset. Post-reaction: k hours at 60 ° C. The batch was - as described in Example 1 - freed from HpO catalytically and concentrated by distillation. At a bottom temperature of 100 ° C. (12 torr) a residue (125 g) remained, which was then totally distilled at 12 torr. The fraction (103 g) passing over between 103 107 C consisted of 3-chloro-2-methyl-1,2-propanediol.

Example 3:

In an apparatus according to Example 1, 1 mol of pentene-1 (70 g) was mixed with 1 mol of formic acid and, with evaporative cooling (approx. 30 _{° C.), with 1.5 mol of H 3} O (k0 £ ig; 128 g ) offset. After a post-reaction time of 8 hours, the system had become 1-phase. It was catalytically freed of HO, neutralized with p0 g of NaOH (h0 ^r , oig) and extracted four times with 100 ml of ethyl acetate each time.

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The ethyl acetate extracts were combined and freed from the solvent by distillation. A pentane-diol residue (crude) of 6k g remained, the amount of which could be increased further by concentrating the aqueous phase to about half and again exhaustively extracted with ethyl acetate.

In the total distillation (12 Torr), Sk g of crude diol gave an amount of 78 g of pure 1,2-pentanediol, which passed over at 115-117 ° C.

The experiment was repeated in a modified stirrer apparatus which, after the reflux condenser, was equipped with a Pressure holding valve was equipped, which is at a ^ Overpressure of 2 atmospheres opened. This enabled the pentene-1-hydroxylation with those given above Use amounts carried out at a temperature of 50 C. will. Under these conditions, both the H_0 dosing time and the sewing reaction-

^{2 2}

time can be reduced by half. The work-up carried out at slightly increased pressure The experiment gave practically the same yields as in the pressureless experiment.

Example ki

In an apparatus according to Example 1, 1 mol of 2,3-dimethyl-butene-2 (8k g) was mixed with 0.6 mol of formic acid (98%; 2b g) and at 55 ° C in the course of k hours with 1, 5 mol of HO (20%; 255 g) are added. After a post-reaction time of k hours, the system had indeed become single-phase, it could

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however, 2 g of olefin can still be removed by distillation (conversion = 95 ¹ ^).

After the usual catalytic H 0 _o decomposition, the mixture was rendered neutral with 50 g of NaOH (25 % strength) and extracted four times in succession with 100 ml of ethyl acetate each time. The remaining aqueous phase was concentrated to half by distillation and extracted again four times with 50 ml of ethyl acetate each time. All

"- 'Ethyl acetate extracts were combined and initially freed from water still dissolved by aceotropic distillation. After the low boilers had been distilled off, a bottom product (98 g; 98 / ό (yield 8? <>) .

Example 5 ^:
20th

In an apparatus according to Example 1, 1 mol of Hepten-3 (98 g) was mixed with 1 mol of formic acid (98 <£ ig; 47 g) at 55 ° C. in the course of 5 hours with 1.5 mol of H ₃ O (35 ^>ig; 146 g) added. Even after a stirring time of 2 hours at 60 ° C., the batch remained 2-phase. The batch was catalytically freed from residual HO and made neutral with 05 g NaOH (40 ± 1 g). The aqueous phase was extracted four times with ethyl acetate (100 ml each time) and concentrated to half

and extracted again twice with ethyl acetate. All Ethyl acetate extracts were added to the organic phase combined and freed from the low boilers by distillation. A bottom product remained (crude 3,4-heptanediol = 132 g) obtained by fine fractionation

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OWGJNAL INSPECTS

- ¹ 13 ° ^c ) in oil yield into the

pure heptanediol-3 , ^ was transferred.

Example 6:

In an apparatus according to Example 1, 1 mol (= 129 g) of 2-ethyl-hexen-2-ol-1 was mixed with 0.7 mol of formic acid (98%; 33 g) and at 55 ° C. over the course of k hours with 1 , 5 mol of H ₃ O ₂ (20 g; 255 g) are added. The batch was then stirred for a further k hours at 60 ° C. and also remained in two phases. The aqueous phase was separated off and the organic phase was washed twice with water (50 ml each time).

All combined aqueous phases were catalytically freed from HO and 65 g NaOH (40% lg) neutral ^ provided. The aqueous phase was then extracted exhaustively with ethyl acetate. The ethyl acetate extract was combined with the organic phase and freed from low boilers by distillation. The remaining bottom product weighed 1 ^ 3 g and could be converted into pure 2-ethylhexanetriol-1,2,3 by high vacuum distillation (0.1 Torr; 90-92 ° C.).

18th September 1979
Dr Sib-El

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Claims (3)

293784Q 79 ZOk AO GERMAN GOLD AND SILVER SCHEIDEANSTALT
10 FORMERLY ROESSLER Veissfrauenstrasse 9. 6000 Frankfurt 1 Patent claims: / ^) ^: 1. / Process for the hydroxylation of 3-chloro-2-met; hylpropen-1, of straight-chain or branched,
unsubstituted or already by 1 to 2
Monoolefins substituted with hydroxyl groups rye k to 7 carbon atoms and terminal or internal double bond, of straight-chain or branched, unsubstituted or already substituted by 1 to 2 hydroxyl groups
Monoolefins with 8 to 10 carbon atoms and an internal double bond or of straight-chain or branched diolefins with h to
10 carbon atoms, characterized that the olefin to be hydroxylated at a temperature between 30 and βθ C rait less than 2 moles of formic acid and less than 2 moles of water 1300K / 054 5. 29378A0 Substance peroxide, each per mole to be hydroxylated Double bond, converts, formic acid with a concentration between 20 and 100 percent by weight and using hydrogen peroxide at a concentration of less than 50 percent by weight, and the concentration of hydrogen peroxide in the aqueous phase of the reaction mixture during the total duration of the reaction below 15 percent by weight holds. 2. The method according to claim 1, characterized in that the reaction is carried out at one temperature between 45 and 60 C. 3. The method according to claim 1 or 2, characterized in that the formic acid in an amount from 0.2 to 0.6 mol per mol of double bond to be hydroxylated is used. k. Process according to one of Claims 1 to 3, characterized in that the hydrogen peroxide is used in an amount of 1.1 to 1.5 mol per mol of double bond to be hydroxylated. 5 · The method according to any one of claims 1 to k, characterized in that hydrogen peroxide with a concentration of 15 to kO weight percent begins.